/*
 * Copyright 2011 MCA
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.mca.qmass.persistence;

import java.util.AbstractList;
import java.util.ArrayList;
import java.util.List;

/**
 * User: malpay
 * Date: 14.11.2011
 * Time: 11:28
 */
public class CursorList<T> extends AbstractList<T> {

    private Cursor<T> cursor;

    private List<T> buffer = new ArrayList<T>();

    public CursorList(Cursor<T> cursor) {
        this.cursor = cursor;
    }

    @Override
    public T get(int index) {
        if (index >= cursor.size()) {
            throw new IndexOutOfBoundsException();
        }

        if (index < cursor.currIndex()) {
            return buffer.get(index);
        }

        while (index != cursor.currIndex()) {
            buffer.add(cursor.next());
        }

        final T next = cursor.next();
        buffer.add(next);
        return next;
    }

    @Override
    public int size() {
        return cursor.size();
    }
}
